Ratchet Wrench

ABSTRACT

A ratchet wrench with a crescent groove housing a ratchet-pawl mechanism. The ratchet-pawl mechanism has a ratchet-pawl, a spring and a spring seat with a notch. The crescent groove allows for easy access for assembling and removing the ratchet-pawl mechanism. The new structure renders reduced manufacturing and repairing cost.

DESCRIPTION OF RELATED ART

The present application relates to a wrench, more particularly, to aratchet wrench that is used for tightening and loosening nuts or boltsfrom locations that are hard to reach.

Note that the points discussed below may reflect the hindsight gainedfrom the disclosed inventions, and are not necessarily admitted to beprior art.

A wrench is a tool used to provide grip and torque in order to turn, orto keep from turning, objects such as nuts and bolts. Common types ofwrenches used include open-end wrench and box-end wrench. There are manyother types of wrenches, for example, the tube wrench, ratcheting boxwrench, flex-head socket wrench, spanner wrench, hammer wrench,adjustable wrench, monkey wrench, pipe wrench, socket wrench, breakerbar, crowfoot wrench, speed wrench, torque wrench, allen wrench, bristolwrench, torx wrench, alligator wrench, cone wrench, die wrench, drumwrench, spark plug wrench, fire hydrant wrench, curb key, etc.

A ratchet wrench is a type of wrench that contains a ratchet mechanismin which allows a socket to be turned without removing the wrench fromthe nut or bolt when cycling the handle backwards and forwards. Theratchet usually contains a small gear or a rack of teeth with aspring-loaded finger known as the pawl which engages the teeth. The pawlis necessary in order to prevent the backwards motion of the gear sothat the bolt or nut can be held in place while the handle of the wrenchis moved back so another round of forward motion can occur in order totighten the bolt or nut further without having to remove the wrench.This mechanism, known as the backlash, provides a convenient way formechanics to work on cars within a tight location and with an improvedease on the human arm. Also, the ratchet wrench is utilized in workshopsthat focus on building or servicing machine tools. They can be used forhome improvement tasks as well.

There are many prior patents that are involved in the art of developinga ratchet wrench. The design of ratchet mechanism has been the centerfor improvement. For example, U.S. Pat. No. 8661945 B1 to ElDessoukydescribes a complicated clamping mechanism to hold the ratchet in place.U.S. Pat. No. 9027444 B2 to Chang designs a magnetic member and a screwnut and multiple limiters within the wrench head to allow for theratchet to rotate. U.S. Pat. No. 9032845 B2 to Lin constructs a ratchetwrench which comprises of multiple recesses for the ratchet, the pawland the rotatable unit within each recess. The structure is cumbersometo assemble and to repair.

The conventional ratchet wrenches still comprise many different partsand units which would require high manufacturing cost as well as highreplacement or repair cost. Improved designs are still needed.

SUMMARY

The present application discloses a new ratchet wrench that is easy tomanufacture and to repair.

In one embodiment, a ratchet wrench comprises of a wrench head, aratchet gear wheel and a ratchet-pawl unit wherein said ratchet-pawlunit is configured with matching teeth with the ratchet gear wheel towithhold the ratchet gear wheel within the wrench head.

In one embodiment, a wrench head comprises a receiving chamber having a“crescent groove” configured to mount a ratchet-pawl unit wherein thecrescent groove is sufficiently sized and shaped to hold theratchet-pawl unit within the receiving chamber.

In another embodiment, the ratchet-pawl unit comprises a pawl, a springand spring-seat structure wherein the spring serves as a connectionmechanism between the pawl and the spring-seat, and the pawl and thespring-seat are configured to match the crescent groove so that the pawlis able to hold and release the ratchet gear wheel from the wheel teethso that the ratchet wheel can rotate.

BRIEF DESCRIPTION OF THE DRAWINGS

The disclosed application will be described with reference to theaccompanying drawings, which show important sample embodiments of theinvention and which are incorporated in the specification hereof byreference, wherein:

FIG. 1 shows a prior art ratchet wrench.

FIG. 2 shows an elevated view of an example ratchet wrench head inaccordance with this application.

FIG. 3A shows a perspective view of an example receiving chamber of anexample ratchet wrench head in accordance with this application.

FIG. 3B shows a cross-section view of an example receiving chamber of anexample ratchet wrench head in accordance with this application.

FIG. 4A shows an expanded view of an example ratchet-pawl unit inaccordance with this application.

FIG. 4B shows an example ratchet-pawl unit assembly in accordance withthis application.

DETAILED DESCRIPTION OF SAMPLE EMBODIMENTS

The numerous innovative teachings of the present application will bedescribed with particular reference to presently preferred embodiments(by way of example, and not of limitation). The present applicationdescribes several embodiments, and none of the statements below shouldbe taken as limiting the claims generally.

For simplicity and clarity of illustration, the following figuresillustrate the general manner of construction, and description anddetails of well-known features and techniques that may be omitted toavoid unnecessarily obscuring the invention. Additionally, elements inthe figures are not necessarily drawn to scale; some areas or elementsmay be expanded to help improve understanding of the embodiments of theinvention.

The terms “first,” “second,” “third,” “fourth,” and the like in thedescription and the claims, if any, may be used for distinguishingbetween similar elements and not necessarily for describing a particularsequential or chronological order. It is to be understood that the termsused are interchangeable. Furthermore, the terms “comprise,” “include,”“have,” and any variations thereof, are intended to cover non-exclusiveinclusions, such that a process, method, article, apparatus, orcomposition that comprises a list of elements is not necessarily limitedto those elements, but may include other elements not expressly listedor inherent to such process, method, article, apparatus, or composition.

The term “ratchet wrench” refers to a mechanical tool having a wrenchhandle and a wrench head capable of receiving a ratcheting mechanismattached to a socket wherein the socket is used to tighten or loosen abolt or a nut. The ratcheting mechanism allows the bolt or nut to berapidly tightened or loosened in small increments without disconnectingthe tool from the fastener.

The term “socket” refers to a structure that is capable of fitting ontoa type of bolt or nut to allow for a wrench to tighten or loosen a boltor a nut. The socket structure may be either independent of a wrenchhandle or integrally built with the wrench handle.

The term “ratcheting mechanism” refers to a gear-like rotatory unit thatis either independently built or integrally built together with a socketstructure of a ratchet wrench.

The term “ratchet head” refers to a structure of a ratchet wrench thatincludes a receiving chamber for receiving and mounting a socketstructure. A ratchet head may be independent of a wrench head or anintegrally built to a wrench head.

The term “crescent groove” refers to a groove structure configuredwithin a ratchet head wherein the groove structure forms an emptycrescent space similar to the shape of a crescent moon.

The term “ratchet-pawl” refers to a structure that interacts with theratcheting rotary unit to either lock or release the ratcheting rotaryunit for not-rotating or free rotating motions.

The term “spring seat” refers to a structure that holds a spring formounting the ratchet-pawl inside the crescent groove so that theratchet-pawl is capable of engaging or disengaging the ratchetingmechanism.

A ratchet wrench is a hand tool in which generally metal handle isattached to a ratcheting mechanism, which attaches to a socket, which inturn fits onto a type of bolt or nut. Pulled or pushed in one direction,the ratchet loosens or tightens the bolt or nut attached to the socket.Turned the other direction, the ratchet does not turn the socket butallows the ratchet handle to be re-positioned for another turn whilestaying attached to the bolt or nut. This ratcheting action allows thefastener to be rapidly tightened or loosened in small increments withoutdisconnecting the tool from the fastener. A switch mechanism is builtinto the ratchet head that allows the user to apply the ratchetingaction in either direction, as needed, to tighten or loosen a fastener.

Independently built sockets may be driven by being attached to thedriving tool via a male/female square connection fitting. Standard sizesof square drives around the world include ¼″, ⅜″, ½″, ¾″, 1″, 1-½″, 2-½″and 3-½″ square drive sizes along with some lesser used drivers such as⅝″ square drive, and spline drives specified in ANSI specifications.This wide range of square drive sizes provides for a wide variety ofsocket types and sizes to suit small to very large nuts and bolts. Somesquare drivers have a through hole to attach the socket to the driversuch as a retaining ring with 0-ring and pin type, or single piecemolded retaining rings, a locking pin, or friction ball. Some commonhand ratchets employ a quick release button on their top for quicksocket release of smaller sockets. The tool chosen to drive the socketwrench ultimately supplies the mechanical advantage needed by the userto provide the torque needed to loosen or tighten the fastener as may berequired. Larger drivers are typically used with higher torque, whilesmaller drivers are used for convenience in smaller low torqueapplications. Very large sockets and drivers are typically powered byhydraulics to achieve torque.

A socket is typically a cylinder which has a female six- or twelve-pointrecessed opening sized to fit over the common male hexagonal head of abolt or nut fastener. The opposite end of the socket wrench may havesquare recess to accept the socket wrench's drive size. Male drivers arealso produced for use with socket head cap screws.

For example, in reference to FIG. 1, a prior art ratchet wrench includesa wrench head 101, wrench handle 10, a rotary gear 20 which isconstructed with a rotary wheel with teeth structure 21, 23 and 210.Within gear 20 is integrally constructed with a polygonal socket 22. Themost common socket shape is hexagonal, or more commonly referred to as“6-point.” A ratchet pawl 30 with matching teeth 31, 32 and 310 to gear20 are part of the switch mechanism that also includes a pin 50 and aswitch 40. A recess groove 12 and hole 13 are built on the wrench head101 for receiving and mounting ratcheting mechanism and socket thatincludes gear 20, switching set 30 and 50 and 40.

However, the independent and separate switching mechanisms 50 and 40need additional manufacturing steps which increase manufacturing cost,assembly cost and cost for repairs. An improved structure of a sockethead for a ratchet wrench is hereby described below.

In reference to FIG. 2, a socket head structure 200 is shown. Forsimplicity, the figured socket head illustrated is an integral piece ofthe wrench head. However the socket head can also be constructedindependent of a wrench head and wrench handle and that can be mountedto a separate wrench head and wrench handle. Socket head 200 includes areceiving chamber 201 in which houses the ratchet-pawl transmission unitthat includes a ratchet rotary unit 211 that contains an integrallyconstructed socket structure 213, a ratchet-pawl 205, a spring 207 and aspring seat 209, where receiving chamber 201 is constructed with acrescent groove 203 for housing the ratchet-pawl assembly. Spring seat209 and ratchet-pawl 205 are configured with a surface that matches thecurvature of the crescent shape of groove 203. In use, the narrowed endsof crescent groove 203 will stop spring seat 209 and ratchet-pawl 205from moving further once they are pulled to the ends by the toque forcewhile the middle section enlarged space will allow spring seat 209 andratchet-pawl 205 to move to be disengaged with the gear teeth of rotaryunit 211 when pulled by the connecting spring 207, but then at relaxedposition can ratchet-pawl 205 re-engage with the gear teeth of rotaryunit 211.

In use, at the relaxed position in the middle section of crescent groove203, ratchet-pawl 205 engages with the gear teeth of rotary unit 211,when rotary unit 211 rotates clockwise, ratchet-pawl 205 will be pulledtowards the narrowing end 206 of crescent groove 203 to the point thatratchet-pawl 205 cannot move further, rendering the engaged rotary unit211 unable to rotate further. Once rotary unit 211 is unable to rotateclockwise direction, continued rotating torque force from the wrenchhandle and wrench head will thus be transferred onto the nut or boltthat is inside socket 213 space to turn the nut to the point when thereis no further space for the wrench handle to turn clockwise. The wrenchfinishes one round of rotating job. Then the wrench head and wrenchhandle can move anticlockwise without detaching from the socket head200, and the rotary unit 211 will pull the engaged ratchet-pawl 205 tomove toward the center section of crescent groove 203, the enlargedspace at the center section allows stressed spring 207 to pullratchet-pawl 205 towards the middle and temporarily disengaging fromrotary unit 211, causing the torque force applied on the wrench head andits receiving chamber 201 disengaged from interacting with the rotatingrotary unit 211 and the socket 213. The wrench handle and head can thusrotates anticlockwise to re-position while the rotating rotary unit 211and the socket 213 stays still and attached to the bolt or nut insidesocket 213.

Once ratchet-pawl 205 is pulled by spring 207 and moves to the middlesection of the crescent groove 203, spring 207 relaxes, and ratchet-pawl205 in relaxed position, with the assistance spring seat 209, is in theright position to re-engage with the gear teeth of rotary unit 211,which stops the wrench to further re-position by rotating anticlockwise,and a user can then start to a second round of rotating clockwise toapply the torque force to the nut or bolt inside socket 213. Spring seat209 provides a stabilization structure to spring 207 and guides the moveof ratchet-pawl 205 so that when ratchet-pawl 205 moves towards the endof crescent groove 203, there is enough stress within spring 207 thatcan pull ratchet-pawl 205 to the middle section to disengage and tore-engage with gear teeth of rotary unit 211.

In reference to FIG. 3A and 3B, an example receiving chamber 300 isshown, in which receiving chamber 300 has a cylindrical shell body 201that is capable of housing a rotary unit and a socket; and at one endthe cylindrical shell body may be extended into a wrench handle 303.Alternatively, receiving chamber 201 may be independently built andfixedly mounted to a wrench head that is connected with a wrench handle.On the receiving cylindrical shell body 201, a crescent groove 203 iscarved into the wall at one side of the shell body (FIG. 3B), preferablyat the side of extension to the wrench handle that provides sufficientsize for carving a crescent groove into. Crescent groove 203 is formedby two side walls 301 and 305 and a semi-circular shaped bottom side 411that are integral part of the cylindrical shell body 201. Thecross-section of the receiving chamber 300 thus forms two inter-crossedcircular spaces 413 and 203 which would respectively house a ratchetrotary gear unit and bolt socket and a ratchet-pawl assembly so that theratchet-pawl assembly housed in the middle of space 203 comes intocontact with the rotary gear unit housed in space 413.

Preferably all the different parts are made of heavy hard metal orstainless steel for providing sufficient durability and resilience.

In reference to FIG. 4A and 4B, elevated views of an exampleratchet-pawl assembly 400 are shown. The ratchet-pawl assembly 400comprises ratchet-pawl 205, spring 207 and spring-seat 209. Ratchet-pawl205 comprises an elongated body in the shape of a first with a sharperend 516 and a wider end 518, a teethed side 517 and a curved side 519.Teethed side 517 provides a surface that are slightly curved in order tointeract with the gear teeth of a ratchet rotary unit while the curvedside 519 provides a matching shape to a crescent groove of a receivingchamber so that ratchet-pawl 205 can slide down the crescent groove tobe disengaged from the gear teeth of a ratchet rotary unit. The sharperend 516 is constructed to fit with the crescent groove's angled end andthe wider end 518 is constructed to interact with spring 207 which inturn interacts with spring-seat 209. A small handle 204 may beconfigured on wider end 518 for mounting spring 207. Spring seat 209 maysimilarly comprises an elongated body in the shape of a wedge with asharper end 515 and a wider end 514, a slightly curved side 510 forfacing and fitting a ratchet rotary unit and a greater curved side 513for fitting with the curvature of a crescent groove. On the wider end514 may be constructed a notch 511 for holding and guiding the movementof spring 207. FIG. 4B shows an assembled ratchet-pawl assembly whereratchet-pawl 205 is fixedly linked to spring seat 209 by spring 207.Notch 511 is constructed to render have an opening on spring seat 209 sothat spring 204 can easily slide into the notch for assembling.

None of the description in the present application should be read asimplying that any particular element, step, or function is an essentialelement which must be included in the claim scope: THE SCOPE OF PATENTEDSUBJECT MATTER IS DEFINED ONLY BY THE ALLOWED CLAIMS. Moreover, none ofthese claims are intended to invoke paragraph six of 35 USC section 112unless the exact words “means for” are followed by a participle.

The claims as filed are intended to be as comprehensive as possible, andNO subject matter is intentionally relinquished, dedicated, orabandoned.

What is claimed is:
 1. A ratchet wrench having a teethed ratchet rotaryunit, comprising: ratchet-pawl assembly comprises a ratchet-pawl havinga teethed side, a spring, and a spring-seat, said spring being mountedbetween said ratchet-pawl and said spring-seat linking said ratchet-pawland said spring-seat together, said and said teethed side of saidratchet-pawl engaging with said teethed ratchet rotary unit when saidspring is relaxed.
 2. The ratchet wrench of claim 1, further comprising:a ratchet socket receiving chamber having a cylindrical shell body,wherein said cylindrical shell body has a first cylindrical portionhousing said teethed ratchet rotary unit, said cylindrical portionhaving an inner wall facing said teethed ratchet rotary unit, and saidcylindrical shell body has an enlarged portion, said enlarged portionhaving a first side wall, a second side wall and a continuouscrescent-shaped bottom wall that form a crescent-shaped groove opening,said crescent-shaped bottom wall merging unto said inner wall of saidcylindrical portion, said crescent groove opening has a center sectionand a first end and second end, said center section being farthest fromsaid ratchet rotary unit, and both said first end and second end beingclosest to said teethed ratchet rotary unit, and a ratchet-pawl assemblybeing disposed within said crescent-shaped groove opening.
 3. Theratchet wrench of claim 2, wherein said spring-seat is configured in ashape of a wedge, said spring-seat having a first side and a secondside, said first side being curved to allow said teethed ratchet rotaryunit to rotate, and said second side being shaped to match said saidcrescent-shaped bottom wall.
 4. The ratchet wrench of claim 2, wherein anotch opening is configured on said spring-seat for sliding-in saidspring, wherein said spring slidingly mounted into said notch opening.5. The ratchet wrench of claim 2, wherein said ratchet-pawl isconfigured in fist-shaped having a an angled and and a wide-end, ahandle being formed on said wide end for mounting said spring.
 6. Theratchet wrench of claim 5, wherein said spring-seat is configured withan angled end and a wide end, said angled end of said ratchet-pawl isdisposed towards the first end of said crescent groove and said wide-endof said ratchet-pawl is disposed toward the center section of saidcrescent groove, and said spring is disposed between said wide-end ofratchet-pawl and said wide end of said spring-seat.